Bridging the Gap: Conference Record [Abstract book, International Conference on AIDS (12th: 1998: Geneva, Switzerland)]

12th World AIDS Conference

Abstracts 11204-11208 23

The immunodominant serotype reactivity was defined by the peptide giving the
strongest blocking signal.
For the quality controle 10 samples were genotyped by using the Heteroduplex
mobility assay (HMA).
Result: 93.50% (187/200) were HIV1 subtype B, 1% (2/200) were subtype A,
0.5 (1/200) were subtype F and 5% (10/200) nontyped.
Documented cases showed that the main route of transmission was heterosexuality with 85.5%. Homosexuality, drug use and transfusion represent 4.5%,
1.6%, and 1.6% respectively.
Conclusion: The Moroccan HIV1 subtypes profile is similar to Western Europe
profile with is predominated by HIV1 subtype B whereas non subtypes B are rare.
There is an active exchange between Morocco and Europe through tourism and
migrants workers, whereas the exchange with the Southern countries in Africa is
less important.
111204 Genetic and biological characterization of Russian HIV-1
subtype B isolate with unusual V3 loop
Tatyana Khanina', L.M. Selimova', L.V. Serebrovskaya2, A.V. Kravchenko2,
V.V. Pokrovsky2. 'The D.I. Ivanovsky Institute of Virology, 16 Gamaleya Street,
123098 Moscow; 2Federal AIDS Centre, Moscow, Russia
Objectives: To investigate Russian HIV-1 subtype B isolate with unusual V3 loop.
Methods: The patient RU0025 was a homosexual male living in Moscow.
He was tested HIV-1-positive in December 1991. Owing to disease progression
patient accepted AZT therapy continually from May 1992. In June 1995, periferal
blood mononuclear cells (PBMCs) were separated using Ficoll-gradient centrifugarion. At that time the CD4 count was 0.14. To isolate virus, patient's PBMCs
were co-cultivated with donors' PBMCs preliminary stimulated for 3 days with
phytohemagglutinin (3 ug/ml). PBMCs cultures were maintained in RPMI 1640
medium containing 10% fetal calf serum, interleukin-2 (10 IU/mL), and antibiotics.
After 4 subsequent co-cultivations the biological phenotype of the isolate, named
95RU25B, was determined, and the 0.4 kbp env gene fragment encompassing
the C2-V3 region of gp120 was amplified using polymerase chain reaction, cloned
in pUC18 vector plasmid, and sequenced.
Results: The isolate 95RU25B formed syntitia in SupT1 cells and was able to
grow in U937.2 cell line, displaying S/L.3 phenotype. Genetic analysis of 95RU25B
revealed that this isolate belonged to HIV-1 env genetic subtype B. However,
genetic distance between 95RU25B and the subtype B prototypic strains, MN and
JRCSF, was 11.3% and 12.9%, respectively. Moreover, the translated amino acids
sequence of the V3 loop had three residues insertion as well as three residue
deletion situated upstream and downstream of the crown of V3, respectively:
ctrpnnntrkririGHIgpgrafyat...igdirqahc.
Conclusion: The ability of 95RU25B to grow both in SupT1 and U937.2 cell
lines may result from unusual structure of the V3 loop.
433*/ 11205 Variability of HIV-2 from patients living in France
Francois Simon, F. Damond, I. Loussert-Ajaka, C. Apetrei, D. Descamps,
G. Collin, F. Brun-Vezinet. Laboratoire de Virologie, Hopital Bichat Claude
Bernard, 46 Rue Henri Huchard, Paris, France
Objective: To study the prevalence of HIV-2 subtypes in patients living in France,
and to investigate the correlation between HIV-2 diversity and patients' origin, risk
groups, clinical outcome and serological reactivities.
Methods: HIV-2 strains originated from patients living in France and included
in the HIV-2 French National Cohort. DNA was directly amplified using specific
env HIV-2 primers from PBMCs by nested PCR and env gene was fully sequenced. Phylogenetic trees were inferred using PHYLIP package. Antigenic
consequences of the strain variability was studied by ELISAs using V3 and gp41
peptides from HIV-1 (group M and group O), HIV-2 and SIV and by evaluating the
cross-reactivity on HIV-1 Western blots.
Results: env gene from 36 HIV-2 strains was sequenced and phylogenetical
analyses classified these strains as belonging to HIV-2 subtype A (n = 24) or
B (n = 12). The intrasubtype variability contrasted with the low HIV-2 replicative
capacity. Within the subtype A strains, all the patients originating from Cape
verde Island and Guinea Bissau formed a separate branch. Subtype B-infected
patients mainly originated from Ivory Coast and Mali. Subtype B strains displayed important cross-reactivity profiles on the HIV-1 antigens, including on the
HIV-1 env product on WB. There were no significant differences in clinical and
epidemiological profiles between subtype A and B - infected patients.
Conclusions: HIV-2 subtypes A and B co-circulate in patients liv in France.
The HIV-2 subtype B important cross-reactivities on the immunodominant epitopes of gp41 (HIV-1) might explain at least in part, the double reactive profiles
mainly recorded in those countries where subtype B prevails. There is no difference in virus biology and clinical presentation between subtypes A and B of
HIV-2.

11206 Differential humoral response to linear epitopes of HIV-2
gp36 envelope glycoprotein
Jackie May', N.J. Berry', K. Ariyoshi2, H. Whittle2, M. Mttchell3, P. Balfe1,
L. Loomis-Price3. Department of Virology, UCLMS, 46 Cleveland Street,
London, UK; 2MRC Laboratories, Fajara, Banjul, Gambia; 3Henry M Jackson
Foundation, 13 Taft Court, Rockville MD, USA
Background: Epidemiological evidence suggests that progression to AIDS fol
lowing infection with HIV-2 is slower than for HIV-1, however, atypical cases of
relatively rapid progressing cases of HIV-2 infection have been observed in The
Gambia. The nature of the humoral responses directed at the envelope glycoprotein of HIV-2 in these atypical progressing patients and more typical long term
non-progressors was examined in order to assess the importance of envelope
specific humoral response with respect to disease course during HIV-2 infection.
Methods: Humoral response to whole HIV-2 antigens was assessed by Serodia-HIV1/2 passive particle-agglutination test, and surface envelope glycoprotein
by EIA on recombinant mammalian expressed surface envelope glycoprotein
(rgp105) derived from the Gambian isolate HIV-21SY/6669. To examine in further
detail the nature of the humoral response directed at the envelope glycoprotein
of HIV-2, mapping of seroreactive linear epitopes in gp160 was performed using
188 overlapping 12 mer oligopeptides modeling HIV-21SY/6669.
Results: We found no strong difference between progressors and non-progressors with regard to humoral response to either whole HIV-2 antigens or rgp105.
However, when linear epitope reactivity profiles of progressor and non-progressor patients were compared two peptides, both representing regions within the
gp36 transmembrane region, were found to be differentially recognised. Further
verification using additional serum samples and linear peptides in an EIA format
showed the humoral response to one of these peptides, aminoacids 645-656
(YELQKLNSWDVF), to be elevated in: non-progressing patients when compared
to progressors (P = 0.09), patients with CD4% of greater than 28% compared to
less than 14% (P = 0.004) and patients with undetectable viral RNA compared to
those with greater than 5000 copies/ml (P = 0.003). This peptide corresponds to a
known broadly neutralizing determinant in HIV-1 that also correlates with disease
stage and progression.
Conclusions: We report elevated humoral response to a linear epitope in HIV-2
envelope in non-progressing HIV-2 patients. The influence that this response has
on phenotypic expression of the virus and pathogenicity is under investigation.
S11207 HIV-2 in Spain: Data from the National Registry up to
December 1997
Vincent Soriano', A. Machuca2, M. Gutierrez2, A. Aguilera3, E. Caballero4.
Calle Rafael Calvo 7, 20 A 28010 Madrid; 2Instituto Carlos IlI, Madrid; 3Hospital
Xeral, Santiago; 4 Hospital Vail d'Hebron, Barcelona, Spain
Objectives: To describe the main characteristics of subjects with HIV-2 infection
reported in Spain up to 31 December 1997, examining case report forms from
the HIV-2 National Registry database.
Material and Methods: The HIV-2 Spanish Study Group was founded in 1990,
and includes participants from more than 30 diagnostic centers distributed for
all the Spanish geography. An annual meeting is organized since 1991, which
provides the opportunity to report and discuss the recent identified cases. Serological (EIA, LIA, Western blot) and/or genetic methods are requested to confirm
HIV-2 infection.
Results: since 1988, when the first 3 cases of HIV-2 infection were identified
in 3 African immigrants living in Barcelona, up to January 1998, a total number
of 72 cases of infection have been reported. 56 (77.8%) of them were men. All
cases were adults except for one boy who acquired the infection vertically. Most
individuals were originated from African countries (N = 51), but a prostitute had
been born in Portugal. The remaining cases were Spanish native subjects. The
route of infection was through heterosexual contact in most individuals, although
6 cases were homosexual men, and 3 had been IDUs. Up to now, only 12 (16.7%)
of subjects have developed AIDS, meanwhile the rest remains asymptomatic. In
5 individuals, co-infection with HIV-1 was confirmed by both serologic and PCR
methods. HIV-2 subtypes have been examined in 12 samples: 8 belonged to
subtype A (4 Spanish natives, and 4 Africans) and 4 to subtype B. It is noteworthy
that all patients coming from Equatorial Guinea were infected with B subtypes,
as well as one Spanish native seaman who had been working in the West Coast
of Africa during many years. Overall, there is no evident increase in the number
of reported cases over time. Cases tend to be concentrated around large cities:
Madrid (n = 28), Barcelona (n = 20), Vigo (n = 5), and San Sebastian (n = 4).
Conclusion: HIV-2 infection is currently circulating in Spain, although with low
prevalence and without evident increase over time. The main HIV-2 subtypes, A
and B, are recognized in both Spanish natives and Africans. However, all patients
coming from Equatorial Guinea, a former Spanish colony, carried the B subtype.
111208 A Rev/RRE-like mechanism regulates the expression of
the human endogenous retrovirus HERV-K
Johannes Loewer, Christine Magin, R. Loewer. Paul-Ehrlich-lnstitut;
Paul-Ehrlich-STR.51-59; 63225 Langen, Germany
Objectives: HERV-K is a moderately repetitive endogenous retrovirus family in
the genomes of primates and humans. It codes for the retrovirus-like particles
HTDV detected in human teratocarcinoma cell lines. HTDV/HERV-K is related
to D-type retroviruses. However HERV-K expresses a protein - cORF - that has
no counterpart in D-type retroviruses. In complexly regulated retroviruses (e.g.
lentiviruses and T-cell leukemia viruses), the coordinated expression of accessory

and structural genes depends on the presence of a trans-acting viral protein (Rev
or Rex) and of a responsive element (RRE or RxRE) on the viral RNA transcripts.
cORF has some properties, similar to Rev and Rex namely a leucine rich domain
and a nuclear localization. Assuming that cORF is a Rev homolog, we set out to
identify a cORF responsive element.
Methods: The model system we used has been established and kindly provided by B. Felber and G. Pavlakis (Frederick). In short, a construct composed